my moms 2002 grand marquis's windshield wipers died out on her in a snow storm after a big wave of snow from a truck washed onto her windshield on highway, the wipers still make noise but both arms dont move with the motor , i thought it might be a shear pin of some sort but both arms move together when ya move them with your hands, please if any of you guys have had this problem or know of a secret to fix it without taking it to the mechanic